Mathematical Programming Approach for the Design of Intensified Thermally Coupled Distillation Sequences.

Abstract

In this work we present a methodology that transform insights from the conceptual design of intensified thermally coupled distillation in a set of logical expressions and mathematical models that can be integrated in a mathematical programming environment with the objective of systematically generate column sequences with a reduced number of actual columns (lower than N-1 columns, where N is the number of components). Some of the alternatives considered are Divided Wall Columns (DWC); Columns with vertical partitions, Kaibel like configurations, Elimination of transfer blocks, Extended DWC (including columns with vertical partitions) with external liquid transfer.The combination of all these alternatives provides a new rich space of alternatives, some of them not known before that should be taken into account in the design of distillation based separation systems. Some examples illustrate the procedure.

Dynamic Performance of a Complex Distillation System to Separate a Five‐Component Hydrocarbon Mixture

“…a. This structure has been previously presented by Caballero and Reyes‐Labarta , obtaining savings of 10 % in total annual costs through this intensified system. To simulate and analyze such system in a virtual environment, the thermodynamically equivalent structure shown in Fig.…”

“…b were performed in Aspen Plus V8.4. Structural design parameters for each column were taken from the work of Caballero and Reyes‐Labarta and are presented in Tab. , where N T is the total number of stages, N F is the stages where feed streams enter to the column, and N SS are the stages from which side streams are withdrawn.…”

“…The synthesis methodology has been previously reported by Caballero and Reyes‐Labarta . In this sub‐section, the method will be briefly explained.…”

“…To the knowledge of the authors, there are only few works dealing with the dynamic properties of dividing‐wall systems for the separation of mixtures with four or more components. Thus, this work will give insights about the dynamic performance of a complex dividing‐wall system for the separation of a five‐component mixture, which has been reported as an energy‐saving approach in previous works .…”

“…In this work, the dynamic performance of a complex five‐component DWC system, previously reported by Caballero and Reyes‐Labarta , is analyzed under different operating points, including the one with minimum energy consumption. The control analysis properties are evaluated with the application of the singular value decomposition technique.…”